1. Technical Field
The present invention relates to a semiconductor device, and a method of manufacturing a semiconductor device.
2. Related Art
An IGBT is known as one of power semiconductor devices (see Patent Documents 1 to 3, for example).
Patent Document 1: Japanese Patent Application Publication No. H6-69509
Patent Document 2: Japanese Patent Application Publication No. 2002-305305
Patent Document 3: Japanese Patent Application Publication No. 2006-324431
In an IGBT, a strong electric field acts on a p-n junction between an n type drift region and a p type collector region on a rear surface side at the time when a reverse bias is applied. For this reason, if there is a defect at the p-n junction portion, a reverse withstanding voltage lowers.